Motor vehicles with assistance systems such as a lane change assistance system are known in DE 103 18 741 A1. In the process, one or several sensors monitor the surroundings of the vehicle at the sides and at the rear. A control unit calculates whether an upcoming lane change could result in a hazardous situation. If there is a high degree of danger, an optical display device, usually an LED, is triggered on the exterior mirror, which should give an indication of the danger. Thereby, it is intended that the hazardous situation is continually reproduced by the optical display means.
However, systems of this type have the disadvantage that the perceptibility of the optical signal is not guaranteed in different ambient light conditions. A fixed, pre-determined light intensity can lead to irritating the driver in darkness, and in contrast, cannot be detected at all in bright sunshine. A solution is known in DE 10 2005 038 179 B4, in which the brightness of the light source can be changed by the control unit, depending on a measurand provided to the control device, showing a measurement for the ambient brightness.
Instead of operating with a pre-determined brightness, the display here adapts to the current ambient brightness. This means that in the case of relatively dark surroundings, the light source of the optical display device only illuminates very weakly, so that whilst the display can still clearly be seen with a glance in the direction of the exterior mirror, it does not irritate or even dazzle. In very bright surroundings, for example, in bright sunshine, the light source then accordingly illuminates brightly, so that its light is not covered by the sunlight. The optical perceptibility is therefore adapted to the needs of the driver.
No optical solution is suggested in addition to this. In optical displays, there is also always the problem that the display surface should be illuminated homogeneously, and in the case of use in a motor vehicle, should also harmoniously fit into the external contour of the vehicle.
The object of the invention is to create an optical display, which meets the high demands of a variable, homogeneously illuminated display.